Wayne Kerr AP10030, User & Service Manual

Page: 22 / 70

22 Wayne Kerr AP 1kW Power Supplies • Issue 2
6.4.2 Remote Voltage Sensing
9 10 11 12 13
-S -S
-
-
-
+S
+
+
+
Output busbars
Links removed
Load
Screened
sense leads
Route load leads
close together
Connect:
+sense to +ve load terminal
-sense to -ve load terminal
0.1uF Capacitor
across load
Fig 6.3. Connections for remote voltage sensing
Remote voltage sensing must be used where the load lead resistance is such that it causes
the regulation at the load to be unacceptably poor. Connecting the sense terminals to the
supply output at the load (rather than at the output busbars) will overcome this problem.
This is because the control circuitry will now monitor the voltage across the load.
To connect for remote sensing proceed as follows:
a) Switch off a.c. power, wait 30 seconds, then remove rear terminal cover.
b) Remove the two links joining barrier strip terminals 10 and 11, and 12 and 13.
c) Connect the sense leads from the sense terminals to the load as shown in the diagram.
Fig. 6.3 .
d) Connect the load and replace the terminal cover.
e) Connect 0.1µF capacitor if necessary.
N.B. - The sense leads only carry a few milliamps of current and can be of a light gauge
wire. To minimise pick up they should be a screened, twisted pair of leads, since any
noise picked up will appear on the output. If the sense leads become disconnected the
load voltage will tend to rise above the set value. This rise will be limited by internal
circuitry to approximately 10-20% of the set value.
Load leads should be made of heavy gauge wire. As well as giving the necessary current
carrying capability, this helps reduce the volt drop along the load lead between the output
and sense terminals. Such a volt drop must not exceed 0.5V.
Leads should be kept as short as possible. If long leads are used an additional capacitor,
connected across the load, may be required. See section 6.2.